The marginal cost of producing an item is the rate at which its cost changes with respect to the number of items produced. Thus, C is the cost of producing x items and the marginal cost is Cx. The marginal cost approximates the additional cost necessary to produce one additional item. Thus, Cx is the approximate cost incurred to produce the x+1 nth item. Suppose the total cost of producing x items is given by the function C = 0.001x + 0.025x^2 + 3x + 5. Determine the marginal cost of producing the 51st item.